It is proposed to study in vivo the effect of the elevated tissue levels of acetate found in an animal metabolizing ethanol upon the brain free cytoplasmic (acetyl-CoA)/(CoA) ratio. The thermodynamically important free (acetyl-CoA/(CoA) ratio in tissue seems to be different from the ratio of the total measured nucleotides and in liver metabolizing ethanol the importance of considering the free ratio instead of the total ratio has already been demonstrated. It is proposed to extend these studies to brain because of potentially important implications of this ratio for acetyl-choline synthesis. If brain reacts similar to the liver, an increased pressure for acetyl-choline synthesis will be demonstrated during ethanol metabolism whether or not there is a change in the steady-state level of acetyl-choline. For metabolite measurements perchloric acid extracts of quick frozen brain samples (obtained with a rapid brain freezing device) will be used. The individual metabolites will be measured enzymatically (spectrophotometrically of fluorometrically except for choline and acetyl-choline which require levelling techniques). The suitability of the free (acetyl-CoA)/(CoA) ratios calculated from the ATP-citrate lyase and acetyl-CoA synthetase reactions in brain will be explored and compared with the ratio of the total nucleotides. The effect of ethanol upon these ratios will be calculated and the possble relationship between these ratios and the brain acetyl-choline content will be examined.